1. Field of the Invention
The present invention relates to an electro-developing type video camera using an electro-developing recording medium in which an optical image obtained through a photographing lens system is electronically and directly recorded and developed as a visible image in very little time.
2. Description of the Related Art
Such an electro-developing recording medium, per se is known. For example, Japanese Unexamined Patent Publication No. 5-2280 and U.S. Pat. No. 5,424,156 disclose one type of electro-developing recording medium comprising an electrostatic information recording medium and an electric charge keeping medium. The electrostatic information recording medium includes a photoconducting layer and an inorganic oxide material layer, and the electric charge keeping medium includes a liquid crystal display, both the mediums being combined to face each other with a small gap therebetween. An electro-developing type camera using the electro-developing recording medium is already proposed, and is referred to as an electro-developing type camera hereinafter.
In the electro-developing type camera, a voltage is applied between the electrostatic information recording medium and the electric charge keeping medium, and an optical image is formed on the electrostatic information recording medium by a photographing lens system, during the application of the voltage. An electric charge distribution is produced over the electrostatic information recording medium in accordance with a light intensity distribution of the optical image formed thereon, so that the intensity of an electric field acts on the liquid crystal of the electric charge keeping medium in accordance with the electric charge distribution. Thus, an image derived from the optical image is reproduced in the electric charge keeping medium as a visible image. Namely, as soon as the optical image is formed on the electrostatic information recording medium, the image is developed in the electric charge keeping medium.
The electro-developing type camera also includes an image reader comprising a CCD (charge-coupled device) line sensor for optically and electronically reading the image recorded and developed in the electro-developing recording medium, and the read image signals obtained from the CCD line sensor may be processed in various manners. For example, the read image signals may be stored in second recording medium, such as an IC memory card, a floppy disk a hard disk or the like. Also, the read image signals may be transfered from the camera to an external processing device such as computer, a printer, a TV monitor and so on for reproducing the image thereby.
The provision of the image reader results in the camera being bulky, because the image reader further comprises a light source for illuminating the developed image of the electro-developing recording medium, and an optical lens system for focusing the illuminated image at a light receiving surface of the CCD line sensor, and because the image reader must be relatively moved with respect to the electro-developing recording medium, such that the recorded and developed image held therein can be scanned with the light source associated with the CCD line sensor.
Accordingly, it is desirable that the image reader be compactly constituted for the electronic color still video camera's bulkiness to be reduced.
Therefore, an object of the present invention is to provide an electronic color still video camera having an electro-developing recording mediume, and constituted such that an image reader for optically and electronically reading an image recorded and developed on the electro-developing recording medium is compactly arranged so that a size of the camera can become as small as possible.
In accordance with the present invention, there is provided an electro-developing type camera using an electro-developing recording medium, comprising: photographing means for forming an optical image of an object to be photographed in the electro-developing recording medium; flash means for emitting light rays to illuminate the object at an execution of a photographing operation, if necessary; image-sensing means for optically and electronically sensing (or reading) the image formed in the electro-developing recording medium; and optical guide system means for guiding the light rays, emitted from the flash means, to the electro-developing recording medium to illuminate the formed image thereof during the optical and electronic sensing executed by the image-sensing means.
In this camera, the flash means may be constituted as a pop-up type flash which is movable between a pop-up position for the photographing operation and a stowed position for the optical and electronic sensing of the formed image of the electro-developing recording medium. In this case, the camera may further comprise: position detection means for detecting which position of the flash means is selected; means for disabling the photographing operation when positioning the flash means at the stowed position; and means for disabling the optical and electronic sensing or reading of the formed image of the electro-developing recording medium when positioning the flash means at the pop-up position.
Preferably, the optical and electronic sensing (or reading) of the formed image of the electro-developing recording medium is carried out as a scanning operation, in which the formed image of the electro-developing recording medium is scanned by the illumination of light rays guided by the optical guide means. In this case, the camera may further comprise: optical detection means for a part of the light rays emitted from the flash means; and emission controlling means for controlling the emission of light rays from the flash means so as to keep an amount of light rays for the illumination of the formed image of the electro-developing recording medium constant at each of plural scanning steps.
Preferably, the image-sensing means includes a carriage member carrying a scanner mirror, a scanner optical system, and a line sensor aligned with each other and supported thereby, and is intermittently moved step by step along the electro-developing recording medium during the scanning operation, such that the electro-developing recording medium passes through a space between the scanner mirror and scanner optical system. The scanner mirror is arranged to reflect the light rays, guided by the optical guide means, to the scanner optical system by which the light rays are focussed on a linear light receiving surface of the line sensor.
In accordance with the present invention, there is also provided an electro-developing type camera using an electro-developing recording medium, comprising: photographing means for forming an optical image of an object to be photographed in the electro-developing recording medium; flash means for emitting light rays to illuminate the object at an execution of a photographing operation, if necessary; image sensing means for executing a scanning operation to optically and electronically sense or read the formed image of the electro-developing recording medium, the scanning operation including a plurality of scanning steps carried out by intermittently and relatively moving step by step the image reader means with respect to the formed image of the electro-developing recording medium; and optical guide system means for guiding the light rays, emitted from the flash means, to the image sensing means which illuminates the formed image of the electro-developing recording medium with the guided light rays for the optical and electronic sensing of the formed image thereof, wherein the emission of light rays from the flash means is carried out whenever each of the scanning steps of the scanning operation is executed by the image sensing means.
Similar to the first-mentioned camera, the flash means may be constituted as a pop-up type flash which is movable between a pop-up position for the photographing operation and a stowed position for the scanning operation. In this cases the camera may further comprise: position detection means for detecting which position of the flash means is selected; means for disabling the photographing operation when positioning the flash means at the stowed position; and means for disabling the scanning operation when positioning the flash means at the pop-up position. The camera may further comprise: optical detection means for detecting a part of the light rays emitted from the flash means; and emission controlling means for controlling the emission of light rays from the flash means so as to keep an amount of light rays for the illumination of the formed image of the electro-developing recording medium constant at each of the scanning steps of the scanning operation.